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5. BoronName: Boron
Boron is a Group 13 element. Boron has properties which are borderline between metals and non-metals. It is a semiconductor rather than a metallic conductor. Chemically it is closer to silicon than to aluminium, gallium, indium, and thallium. Crystalline boron is inert chemically and is resistant to attack by boiling HF or HCl. When finely divided it is attacked slowly by hot concentrated nitric acid. Compounds of boron (Arabic Buraq from Persian Burah) have been known of for thousands of years. In early Egypt, mummification depended upon an ore known as natron, which contained borates as well as some other common salts. Borax glazes were used in China from 300 AD, and boron compounds were used in glassmaking in ancient Rome. The element was not isolated until 1808 by Sir Humphry Davy, Gay-Lussac and L. J. Thenard, to about 50 percent purity. These men did not recognize the substance as an element. It was Jons Jacob Berzelius in 1824 who identified boron as an element. The first pure boron was produced by the American chemist W. Weintraub in 1909. Elemental boron and borates are not toxic and therefore do not require special precautions while handling. Some of the more exotic boron hydrogen compounds, however, are toxic and do require special handling care. Quick links
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